The background description provided herein is for the purpose of generally presenting the context of the present invention. The subject matter discussed in the background of the invention section should not be assumed to be prior art merely as a result of its mention in the background of the invention section. Similarly, a problem mentioned in the background of the invention section or associated with the subject matter of the background of the invention section should not be assumed to have been previously recognized in the prior art. The subject matter in the background of the invention section merely represents different approaches, which in and of themselves may also be inventions. Work of the presently named inventors, to the extent it is described in the background of the invention section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present invention.
Driving of an instrument or furniture such as, for example, an office desk, a table, a bed, a chair or the like often requires an actuator that is configured to convert a rotary motion into a reciprocating linear motion, so as to cause movements of an adjustable element in a structure in which the actuator is incorporated. For such an actuator, a reversible electric motor is utilized to generate the rotary motion and a transmission member is coupled to the electric motor so as to convert the rotary motion of the electric motor into the reciprocating linear motion of the actuator. Typically, a coil spring is employed in the transmission member to exert a braking force when the electric motor is deactivated. However, when the coil spring exerts the braking force, which is caused by friction, undesirable heat may be generated, which may not only have adverse consequences for the braking effect, but may also damage its surrounding structure. Further, such an actuator is structurally and operably very complicated, and costly in fabrication.
In addition, the electric motor is usually secured in a cabinet of the actuator by a foam plastic block filling an interior of the cabinet entirely, where the foam plastic block defines a recess therein, and the electric motor is tightly received in the recess of the foam plastic block, i.e., the foam plastic block entirely covers the electric motor sides. When the electric motor operates, its rotor is rotating back and forth rapidly, thereby generating heat therein. The use of the foam plastic block may degrade the heat dissipation performance of the actuator. On the other hand, when heated, the foam plastic block is easy to be distorted, easy aging or even to be melt, which may make the recess no longer match the electric motor tightly, thereby causing vibrations of the electric motor, and in turn, affecting the performance of the actuator.
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.